REVIEW URRENT C OPINION
Vitamin D and female fertility Elisabeth Lerchbaum a,b and Thomas Rabe b
Purpose of review Apart from the well known effects of vitamin D on maintaining calcium homeostasis and promoting bone mineralization, there is some evidence suggesting that vitamin D also modulates human reproductive processes. We will review the most interesting and relevant studies on vitamin D and female fertility published over the past year. Recent findings In the past year, several observational studies reported a better in-vitro fertilization outcome in women with sufficient vitamin D levels (30 ng/ml), which was mainly attributed to vitamin D effects on the endometrium. One randomized controlled trial found an increased endometrial thickness in women with polycystic ovary syndrome (PCOS) receiving vitamin D during intrauterine insemination cycles. Further, vitamin D supplementation had a beneficial effect on serum lipids in PCOS women. Vitamin D treatment improved endometriosis in a rat model and increased vitamin D intake was related to a decreased risk of incident endometriosis. Vitamin D was also favorably associated with primary dysmenorrhea, uterine leiomyoma, and ovarian reserve in late reproductive aged women. Summary In women undergoing in-vitro fertilization, a sufficient vitamin D level (30 ng/ml) should be obtained. Vitamin D supplementation might improve metabolic parameters in women with PCOS. A high vitamin D intake might be protective against endometriosis. Keywords endometriosis, fertility, in-vitro fertilization, polycystic ovary syndrome, vitamin D
INTRODUCTION Vitamin D has been well known for its function in maintaining calcium homeostasis and promoting bone mineralization [1]. Vitamin D is a steroid hormone and approximately 80–90% of vitamin D is produced in the skin after sunlight exposure. A small amount of the body’s total vitamin D is also derived from diet and/or supplements [1]. Vitamin D deficiency is highly prevalent among women of reproductive age [2,3,4 ]. The increasing prevalence is caused by obesity, changes in lifestyle, and reduced sun exposure [5]. There is some evidence that in addition to sex steroid hormones, vitamin D also modulates reproductive processes in women and men. This notion is supported by the fact that the vitamin D receptor (VDR) and vitamin D-metabolizing enzymes are found in human reproductive tissues [6]. The focus of this review is the examination of recent research evidence relating to vitamin D and female fertility, including in-vitro fertilization (IVF) outcome, polycystic ovary syndrome (PCOS), endometriosis, and other conditions associated with female infertility. Several studies published over &
the last year were devoted to the role of vitamin D in female fertility and the main findings are shown in Figure 1. The role of vitamin D in male fertility, pregnancy, the perinatal period, lactation as well as earlier articles on vitamin D and female fertility have been comprehensively reviewed elsewhere [6–8] and are not included here.
IN-VITRO FERTILIZATION In 2010, a potential role of vitamin D in IVF has been suggested as pregnancy rates after IVF were reported to be higher in women who are vitamin D sufficient
a
Division of Endocrinology and Metabolism, Department of Internal Medicine, Medical University of Graz, Graz, Austria and bUniversity Women’s Hospital, Heidelberg, Germany Correspondence to Elisabeth Lerchbaum, MD, Division of Endocrinology and Metabolism, Department of Internal Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036 Graz, Austria. Tel: +43 316 385 12383; fax: +43 316 385 13428; e-mail: elisabeth.lerchbaum@meduni graz.at Curr Opin Obstet Gynecol 2014, 26:145–150 DOI:10.1097/GCO.0000000000000065
1040-872X ß 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins
www.co-obgyn.com
Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
Fertility
KEY POINTS Vitamin D sufficiency is associated with a better IVF outcome compared with vitamin D deficiency, which is mainly related to endometrial factors. Vitamin D supplementation might improve reproductive and metabolic health in women with PCOS. High vitamin D intake and levels might protect women against incident endometriosis. Vitamin D supplementation might improve primary dysmenorrhea.
ratio (OR) of clinical pregnancy was four times higher in non-Hispanic white women with sufficient vitamin D levels (>30 ng/ml) compared with women with vitamin D deficiency (
Vitamin D and female fertility Elisabeth Lerchbaum a,b and Thomas Rabe b
Purpose of review Apart from the well known effects of vitamin D on maintaining calcium homeostasis and promoting bone mineralization, there is some evidence suggesting that vitamin D also modulates human reproductive processes. We will review the most interesting and relevant studies on vitamin D and female fertility published over the past year. Recent findings In the past year, several observational studies reported a better in-vitro fertilization outcome in women with sufficient vitamin D levels (30 ng/ml), which was mainly attributed to vitamin D effects on the endometrium. One randomized controlled trial found an increased endometrial thickness in women with polycystic ovary syndrome (PCOS) receiving vitamin D during intrauterine insemination cycles. Further, vitamin D supplementation had a beneficial effect on serum lipids in PCOS women. Vitamin D treatment improved endometriosis in a rat model and increased vitamin D intake was related to a decreased risk of incident endometriosis. Vitamin D was also favorably associated with primary dysmenorrhea, uterine leiomyoma, and ovarian reserve in late reproductive aged women. Summary In women undergoing in-vitro fertilization, a sufficient vitamin D level (30 ng/ml) should be obtained. Vitamin D supplementation might improve metabolic parameters in women with PCOS. A high vitamin D intake might be protective against endometriosis. Keywords endometriosis, fertility, in-vitro fertilization, polycystic ovary syndrome, vitamin D
INTRODUCTION Vitamin D has been well known for its function in maintaining calcium homeostasis and promoting bone mineralization [1]. Vitamin D is a steroid hormone and approximately 80–90% of vitamin D is produced in the skin after sunlight exposure. A small amount of the body’s total vitamin D is also derived from diet and/or supplements [1]. Vitamin D deficiency is highly prevalent among women of reproductive age [2,3,4 ]. The increasing prevalence is caused by obesity, changes in lifestyle, and reduced sun exposure [5]. There is some evidence that in addition to sex steroid hormones, vitamin D also modulates reproductive processes in women and men. This notion is supported by the fact that the vitamin D receptor (VDR) and vitamin D-metabolizing enzymes are found in human reproductive tissues [6]. The focus of this review is the examination of recent research evidence relating to vitamin D and female fertility, including in-vitro fertilization (IVF) outcome, polycystic ovary syndrome (PCOS), endometriosis, and other conditions associated with female infertility. Several studies published over &
the last year were devoted to the role of vitamin D in female fertility and the main findings are shown in Figure 1. The role of vitamin D in male fertility, pregnancy, the perinatal period, lactation as well as earlier articles on vitamin D and female fertility have been comprehensively reviewed elsewhere [6–8] and are not included here.
IN-VITRO FERTILIZATION In 2010, a potential role of vitamin D in IVF has been suggested as pregnancy rates after IVF were reported to be higher in women who are vitamin D sufficient
a
Division of Endocrinology and Metabolism, Department of Internal Medicine, Medical University of Graz, Graz, Austria and bUniversity Women’s Hospital, Heidelberg, Germany Correspondence to Elisabeth Lerchbaum, MD, Division of Endocrinology and Metabolism, Department of Internal Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036 Graz, Austria. Tel: +43 316 385 12383; fax: +43 316 385 13428; e-mail: elisabeth.lerchbaum@meduni graz.at Curr Opin Obstet Gynecol 2014, 26:145–150 DOI:10.1097/GCO.0000000000000065
1040-872X ß 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins
www.co-obgyn.com
Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
Fertility
KEY POINTS Vitamin D sufficiency is associated with a better IVF outcome compared with vitamin D deficiency, which is mainly related to endometrial factors. Vitamin D supplementation might improve reproductive and metabolic health in women with PCOS. High vitamin D intake and levels might protect women against incident endometriosis. Vitamin D supplementation might improve primary dysmenorrhea.
ratio (OR) of clinical pregnancy was four times higher in non-Hispanic white women with sufficient vitamin D levels (>30 ng/ml) compared with women with vitamin D deficiency (
